1. Field of the Invention
This invention relates to a process for manufacturing a blade member of a blade which controls the quantity of a developer used to develop and render visible an electrostatic latent image formed on an image-bearing member, and a process for manufacturing such a blade.
2. Related Background Art
FIG. 1 diagrammatically illustrates a conventional developer quantity control blade 12.
The developer quantity control blade 12 is used in a state that it is brought into pressure contact with a developer-carrying member 14. The developer quantity control blade 12 consists basically of a blade member 10 and a support member 11, and is fastened to a developer container 13 via a fitting member 17.
When such a developer quantity control blade 12 is brought into pressure contact with the developer-carrying member 14, the developer quantity control blade 12 is bent, so that a pressing force F is applied to a developer (not shown) on the developer-carrying member 14 at a contact point 16. Thus, the quantity of the developer carried out of the developer container to the developer-carrying member is controlled (regulated), where a thin layer of the developer is formed and at the same time the developer is provided with stated triboelectric charges (also called “triboelectricity”) at the contact zone.
The developer quantity control blade is commonly formed of a rubber plate, a metallic sheet, a resin plate or a laminate of any of these. The developer quantity control blade is made up from a blade member which is brought into pressure contact with the developer-carrying member and a support member which supports this blade member at a preset position. The face of the blade member that is brought into pressure contact with the developer-carrying member has the function to control the triboelectric charges of the developer. Accordingly, this face is also called a charge control face. The surface layer of this charge control face is also called a charge control layer in some cases.
As blade members used for negative-type toners, plate members of urethane rubbers, urethane resins or polyamide elastomers are used, for example. Also, as developer quantity control blades used for positive-type toners, those obtained by laminating a charge-providing layer of charge-controlled silicone rubber or the like to a metallic sheet are used.
With regard to a non-magnetic toner used in the formation of color images, its thin layer must be formed on a developing sleeve or a developing roller because the toner itself does not have any magnetic properties. In this case, as materials used in the charge control layer, they may include urethane rubbers, polyamide resins, polyamide elastomers, silicone rubbers and silicone resins. The charge control face is finished with good precision.
In recent years, fine-particle toners are used in developing assemblies realizing high-quality and full-color in which an electrophotographic process is applied, and hence the toners are required to be more uniformly pressed against, and made stick to, the developing sleeve or developing roller. However, especially because of the influence of the surface roughness of the charge control face, faulty images such as uneven images and lines may occur.
Japanese Patent Application Laid-open No. 09-050185 discloses a blade member made of a polyamide elastomer or a polyamide resin, used for negative-type toners. As a manufacturing method, a method making use of a mold having a mirror face is disclosed. Also, in blade members made of urethane rubbers, an example is reported in which the charge control face is similarly formed by mold face transfer. However, where the method disclosed in this publication is employed, the surface properties of the charge control face are influenced by how the mold mirror face is maintained and controlled, and there is a possibility of resulting in non-uniform product quality depending on how it has been controlled.
Also with respect to positive-type toners, how the mold mirror face is maintained and controlled is also an important quality control item in developer quantity control blade members made of thermosetting silicone rubbers or urethane rubbers.
Also in respect of positive-type toners, how the mold mirror face is maintained and controlled is also an important quality control item in developer quantity control blade members made of thermosetting silicone rubbers or urethane rubbers.